HER Receptors and Antibodies Thereagainst
The HER family of receptor tyrosine kinases are important mediators of cell growth, differentiation and survival. The receptor family includes four distinct members including epidermal growth factor receptor (EGFR, ErbB1, or HER1), HER2 (ErbB2 or p185neu), HER3 (ErbB3) and HER4 (ErbB4 or tyro2).
EGFR, encoded by the erbB1 gene, has been causally implicated in human malignancy. In particular, increased expression of EGFR has been observed in breast, bladder, lung, head, neck and stomach cancer as well as glioblastomas. Increased EGFR receptor expression is often associated with increased production of the EGFR ligand, transforming growth factor alpha (TGF-α), by the same tumor cells resulting in receptor activation by an autocrine stimulatory pathway. Baselga and Mendelsohn, Pharmac. Ther., 64:127-154 (1994). Monoclonal antibodies directed against the EGFR or its ligands, TGF-α and EGF, have been evaluated as therapeutic agents in the treatment of such malignancies. See, e.g., Baselga and Mendelsohn., supra; Masui et al., Cancer Research, 44:1002-1007 (1984); and Wu et al., J. Clin. Invest., 95:1897-1905 (1995).
The second member of the HER family, p185neu, was originally identified as the product of the transforming gene from neuroblastomas of chemically treated rats. The activated form of the neu proto-oncogene results from a point mutation (valine to glutamic acid) in the transmembrane region of the encoded protein. Amplification of the human homolog of neu is observed in breast and ovarian cancers and correlates with a poor prognosis (Slamon et al., Science, 235:177-182 (1987); Slamon et al., Science, 244:707-712 (1989); and U.S. Pat. No. 4,968,603). To date, no point mutation analogous to that in the neu proto-oncogene has been reported for human tumors. Overexpression of HER2 (frequently but not uniformly due to gene amplification) has also been observed in other carcinomas including carcinomas of the stomach, endometrium, salivary gland, lung, kidney, colon, thyroid, pancreas and bladder. See, among others, King et al., Science, 229:974 (1985); Yokota et al., Lancet, 1:765-767 (1986); Fukushige et al., Mol Cell Biol., 6:955-958 (1986); Guerin et al., Oncogene Res., 3:21-31 (1988); Cohen et al., Oncogene, 4:81-88 (1989); Yonemura et al., Cancer Res., 51:1034 (1991); Borst et al., Gynecol. Oncol., 38:364 (1990); Weiner et al., Cancer Res., 50:421-425 (1990); Kern et al., Cancer Res., 50:5184 (1990); Park et al., Cancer Res., 49:6605 (1989); Zhau et al., Mol. Carcinog., 3:254-257 (1990); Aasland et al., Br. J. Cancer, 57:358-363 (1988); Williams et al., Pathobiology, 59:46-52 (1991); and McCann et al., Cancer, 65:88-92 (1990). HER2 may be overexpressed in prostate cancer (Gu et al., Cancer Lett., 99:185-9 (1996); Ross et al., Hum. Pathol., 28:827-33 (1997); Ross et al., Cancer, 79:2162-70 (1997); and Sadasivan et al., J. Urol., 150:126-31 (1993)).
HER2 amplification/overexpression is an early event in breast cancer that is associated with aggressive disease and poor prognosis. HER2 gene amplification is found in 20-25% of primary breast tumors (Slamon et al., Science, 244:707-12 (1989); Owens et al., Breast Cancer Res Treat, 76:S68 abstract 236 (2002)). HER2 positive disease correlates with decreased relapse-free and overall survival (Slamon et al., Science, 235:177-82 (1987); Pauletti et al., J Clin Oncol, 18:3651-64 (2000)). Amplification of the HER2 gene is associated with significantly reduced time to relapse and poor survival in node-positive disease (Slamon et al. (1987); Pauletti et al. (2000)) and poor outcome in node-negative disease (Press et al., J Clin Oncol, 1997; 15:2894-904 (1997); Pauletti et al. (2000)).
Antibodies directed against the rat p185neu and human HER2 protein products have been described.
Drebin and colleagues have raised antibodies against the rat neu gene product, p185neu See, for example, Drebin et al., Cell, 41:695-706 (1985); Myers et al., Meth. Enzym., 198:277-290 (1991); and WO94/22478. Drebin et al., Oncogene, 2:273-277 (1988) report that mixtures of antibodies reactive with two distinct regions of p185neu result in synergistic anti-tumor effects on neu-transformed NIH-3T3 cells implanted into nude mice. See also U.S. Pat. No. 5,824,311 issued Oct. 20, 1998.
Hudziak et al., Mol. Cell. Biol., 9(3):1165-1172 (1989) describe the generation of a panel of HER2 antibodies which were characterized using the human breast tumor cell line SK-BR-3. Relative cell proliferation of the SK-BR-3 cells following exposure to the antibodies was determined by crystal violet staining of the monolayers after 72 hours. Using this assay, maximum inhibition was obtained with the antibody called 4D5 which inhibited cellular proliferation by 56%. Other antibodies in the panel reduced cellular proliferation to a lesser extent in this assay. The antibody 4D5 was further found to sensitize HER2-overexpressing breast tumor cell lines to the cytotoxic effects of TNF-α. See also U.S. Pat. No. 5,677,171 issued Oct. 14, 1997. The HER2 antibodies discussed in Hudziak et al. are further characterized in Fendly et al., Cancer Research, 50:1550-1558 (1990); Kotts et al., In Vitro, 26(3):59A (1990); Sarup et al., Growth Regulation, 1:72-82 (1991); Shepard et al., J. Clin. Immunol., 11(3):117-127 (1991); Kumar et al., Mol. Cell. Biol., 11(2):979-986 (1991); Lewis et al., Cancer Immunol. Immunother. 37:255-263 (1993); Pietras et al., Oncogene, 9:1829-1838 (1994); Vitetta et al., Cancer Research, 54:5301-5309 (1994); Sliwkowski et al., J. Biol. Chem., 269(20):14661-14665 (1994); Scott et al., J. Biol. Chem., 266:14300-5 (1991); D'souza et al., Proc. Natl. Acad. Sci., 91:7202-7206 (1994); Lewis et al., Cancer Research, 56:1457-1465 (1996); and Schaefer et al., Oncogene, 15:1385-1394 (1997).
A recombinant humanized version of the murine HER2 antibody 4D5 (huMAb4D5-8, rhuMAb HER2, trastuzumab or HERCEPTIN®; U.S. Pat. No. 5,821,337) is clinically active in patients with HER2-overexpressing metastatic breast cancers that have received extensive prior anti-cancer therapy (Baselga et al., J. Clin. Oncol., 14:737-744 (1996)). Trastuzumab received marketing approval from the Food and Drug Administration Sep. 25, 1998 for the treatment of patients with metastatic breast cancer whose tumors overexpress the HER2 protein. Trastuzumab is indicated for weekly treatment of patients both as first-line therapy in combination with paclitaxel and as a single agent in second- and third-line therapy.
In clinical trials, HERCEPTIN® has shown a survival benefit when used in combination with chemotherapy in metastatic breast cancer patients. In December 2001, Genentech received FDA approval to include data that showed a 24 percent increase in median overall survival for women with HER2-positive metastatic breast cancer treated initially with HERCEPTIN® and chemotherapy compared to chemotherapy alone (median 25.1 months compared to 20.3 months).
HERCEPTIN® has been used in combination with various chemotherapeutic agents, including taxoids such as paclitaxel (Slamon et al., N. Engl. J. of Med, 344:783-792 (2001); Leyland-Jones et al., J. Clin. Oncol., 21(21):3965-3971 (2003)), and docetaxel (Esteva et at, J. Clin. Oncol., 20(7):1800-1808 (2002); (Extra et al., Breast Cancer Res Treat, 82 (Suppl 1):217 (2003)); taxoids and platinum compounds (Pegram et al., J. Natl. Cancer Inst., 96(10):759-69 (2004); Yardley et al., Breast Cancer Res Treat, 76:S113 abstract 439 (2002)); platinum compound (such as cisplatin or carboplatin) (Robert et al., Ann. Oncol., 15(suppl 3):39 (abstract 144P); (2004); Pegram et al., J Clin Oncol, 16:2659-71 (1998)); vincas such as vinorelbine (NAVELBINE®) (Burstein et al., J. Clin. Oncol., 19(10); 2722-2730 (2001)); aromatase inhibitors such as letrozole and anastrazole (Jones, A., Annals of Oncology, 14:1697-1794 (2003); Wong et al., Breast Cancer Res Treat, 82(Suppl 1):444 (2003)); anti-estrogen such as fulvestrant (FASLODEX®) (Jones, A., supra); gemcitabine (GEMZAR®) (Miller et al., Oncology, 15(2):38-40 (2001); O'Shaughnessy et al., Breast Cancer Res Treat, 69:302 abstract 523 (2001)); liposomal doxorubicin (Theodoulou et al., Proc Am Soc Clin Oncol, 21:216 abstract 216 (2002)); docetaxel/vinorelbine (with G-CSF and quinolone prophylaxis) Limentani et al., Breast Cancer Res Treat, 76:abstract 162 (2002)); epirubicin and cyclophosphomide (Untch et al., Eur. J. Cancer, 40: 988-97 (2004b). See also Pegram et al., J. Natl. Cancer. Inst., 96(10):739-49 (2004) for various combination therapies including trastuzumab.
Other references describing Trastuzumab clinical trials include Bendell et al., Cancer, 97:2972-7 (2003); Clayton et al., Brit. J. Cancer, 91:639-43 (2004); Seidman et al., J. Clin. Oncol., 20:1215-21 (2002); and Ewer et al., Proc. Am. Soc. Clin. Oncol., (abstr. 489) (2002).
Other HER2 antibodies with various properties have been described in Tagliabue et al., Int. J. Cancer, 47:933-937 (1991); McKenzie et al., Oncogene, 4:543-548 (1989); Maier et al., Cancer Res., 51:5361-5369 (1991); Bacus et al., Molecular Carcinogenesis, 3:350-362 (1990); Stancovski et al., PNAS (USA), 88:8691-8695 (1991); Bacus et al., Cancer Research, 52:2580-2589 (1992); Xu et al., Int. J. Cancer, 53:401-408 (1993); WO94/00136; Kasprzyk et al., Cancer Research, 52:2771-2776 (1992); Hancock et al., Cancer Res., 51:4575-4580 (1991); Shawver et al., Cancer Res., 54:1367-1373 (1994); Arteaga et al., Cancer Res., 54:3758-3765 (1994); Harwerth et al., J. Biol. Chem., 267:15160-15167 (1992); U.S. Pat. No. 5,783,186; and Klapper et al., Oncogene, 14:2099-2109 (1997).
Homology screening has resulted in the identification of two other HER receptor family members; HER3 (U.S. Pat. Nos. 5,183,884 and 5,480,968 as well as Kraus et al., PNAS (USA), 86:9193-9197 (1989)) and HER4 (EP patent application Ser. No. 599,274; Plowman et al., Proc. Natl. Acad. Sci. USA, 90:1746-1750 (1993); and Plowman et al., Nature, 366:473-475 (1993)). Both of these receptors display increased expression on at least some breast cancer cell lines.
The HER receptors are generally found in various combinations in cells and heterodimerization is thought to increase the diversity of cellular responses to a variety of HER ligands (Earp et al., Breast Cancer Research and Treatment, 35:115-132 (1995)). EGFR is bound by six different ligands; epidermal growth factor (EGF), transforming growth factor alpha (TGF-α), amphiregulin, heparin binding epidermal growth factor (HB-EGF), betacellulin and epiregulin (Groenen et al., Growth. Factors, 11:235-257 (1994)). A family of heregulin proteins resulting from alternative splicing of a single gene are ligands for HER3 and HER4. The heregulin family includes alpha, beta and gamma heregulins (Holmes et al., Science, 256:1205-1210 (1992); U.S. Pat. No. 5,641,869; and Schaefer et al., Oncogene, 15:1385-1394 (1997)); neu differentiation factors (NDFs), glial growth factors (GGFs); acetylcholine receptor inducing activity (ARIA); and sensory and motor neuron derived factor (SMDF). For a review, see Groenen et al., Growth Factors, 11:235-257 (1994); Lemke, G., Molec. & Cell. Neurosci., 7:247-262 (1996) and Lee et al., Pharm. Rev., 47:51-85 (1995). Recently three additional HER ligands were identified; neuregulin-2 (NRG-2) which is reported to bind either HER3 or HER4 (Chang et al., Nature, 387 509-512 (1997); and Carraway et al., Nature, 387:512-516 (1997)); neuregulin-3 which binds HER4 (Zhang et al., PNAS (USA), 94(18):9562-7 (1997)); and neuregulin-4 which binds HER4 (Harari et al., Oncogene, 18:2681-89 (1999)) HB-EGF, betacellulin and epiregulin also bind to HER4.
While EGF and TGFα do not bind HER2, EGF stimulates EGFR and HER2 to form a heterodimer, which activates EGFR and results in transphosphorylation of HER2 in the heterodimer. Dimerization and/or transphosphorylation appears to activate the HER2 tyrosine kinase. See Earp et al., supra. Likewise, when HER3 is co-expressed with HER2, an active signaling complex is formed and antibodies directed against HER2 are capable of disrupting this complex (Sliwkowski et al., J. Biol. Chem., 269(20):14661-14665 (1994)). Additionally, the affinity of HER3 for heregulin (HRG) is increased to a higher affinity state when co-expressed with HER2. See also, Levi et al., Journal of Neuroscience, 15: 1329-1340 (1995); Morrissey et al., Proc. Natl. Acad. Sci. USA, 92:1431-1435 (1995); and Lewis et al., Cancer Res., 56:1457-1465 (1996) with respect to the HER2-HER3 protein complex. HER4, like HER3, forms an active signaling complex with HER2 (Carraway and Cantley, Cell, 78:5-8 (1994)).
Patent publications related to HER antibodies include: U.S. Pat. Nos. 5,677,171, 5,720,937, 5,720,954, 5,725,856, 5,770,195, 5,772,997, 6,165,464, 6,387,371, 6,399,063, US2002/0192211A1, U.S. Pat. Nos. 6,015,567, 6,333,169, 4,968,603, 5,821,337, 6,054,297, 6,407,213, 6,719,971, 6,800,738, US2004/0236078A1, U.S. Pat. Nos. 5,648,237, 6,267,958, 6,685,940, 6,821,515, WO98/17797, U.S. Pat. Nos. 6,127,526, 6,333,398, 6,797,814, 6,339,142, 6,417,335, 6,489,447, WO99/31140, US2003/0147884A1, US2003/0170234A1, US2005/0002928A1, U.S. Pat. No. 6,573,043, US2003/0152987A1, WO99/48527, US2002/0141993A1, WO01/00245, US2003/0086924, US2004/0013667A1, WO00/69460, WO01/00238, WO01/15730, U.S. Pat. Nos. 6,627,196B1, 6,632,979B1, WO01/00244, US2002/0090662A1, WO01/89566, US2002/0064785, US2003/0134344, WO 04/24866, US2004/0082047, US2003/0175845A1, WO03/087131, US2003/0228663, WO2004/008099A2, US2004/0106161, WO2004/048525, US2004/0258685A1, U.S. Pat. Nos. 5,985,553, 5,747,261, 4,935,341, 5,401,638, 5,604,107, WO 87/07646, WO 89/10412, WO 91/05264, EP 412,116 B1, EP 494,135 B1, U.S. Pat. No. 5,824,311, EP 444,181 B1, EP 1,006,194 A2, US 2002/0155527A1, WO 91/02062, U.S. Pat. Nos. 5,571,894, 5,939,531, EP 502,812 B1, WO 93/03741, EP 554,441 B1, EP 656,367 A1, U.S. Pat. Nos. 5,288,477, 5,514,554, 5,587,458, WO 93/12220, WO 93/16185, U.S. Pat. No. 5,877,305, WO 93/21319, WO 93/21232, U.S. Pat. No. 5,856,089, WO 94/22478, U.S. Pat. Nos. 5,910,486, 6,028,059, WO 96/07321, U.S. Pat. Nos. 5,804,396, 5,846,749, EP 711,565, WO 96/16673, U.S. Pat. Nos. 5,783,404, 5,977,322, 6,512,097, WO 97/00271, U.S. Pat. Nos. 6,270,765, 6,395,272, 5,837,243, WO 96/40789, U.S. Pat. Nos. 5,783,186, 6,458,356, WO 97/20858, WO 97/38731, U.S. Pat. Nos. 6,214,388, 5,925,519, WO 98/02463, U.S. Pat. No. 5,922,845, WO 98/18489, WO 98/33914, U.S. Pat. No. 5,994,071, WO 98/45479, U.S. Pat. No. 6,358,682 B1, US 2003/0059790, WO 99/55367, WO 01/20033, US 2002/0076695 A1, WO 00/78347, WO 01/09187, WO 01/21192, WO 01/32155, WO 01/53354, WO 01/56604, WO 01/76630, WO02/05791, WO 02/11677, U.S. Pat. No. 6,582,919, US2002/0192652A1, US 2003/0211530A1, WO 02/44413, US 2002/0142328, U.S. Pat. No. 6,602,670 B2, WO 02/45653, WO 02/055106, US 2003/0152572, US 2003/0165840, WO 02/087619, WO 03/006509, WO03/012072, WO 03/028638, US 2003/0068318, WO 03/041736, EP 1,357,132, US 2003/0202973, US 2004/0138160, U.S. Pat. Nos. 5,705,157, 6,123,939, EP 616,812 B1, US 2003/0103973, US 2003/0108545, U.S. Pat. No. 6,403,630 B1, WO 00/61145, WO 00/61185, U.S. Pat. No. 6,333,348 B1, WO 01/05425, WO 01/64246, US 2003/0022918, US 2002/0051785 A1, U.S. Pat. No. 6,767,541, WO 01/76586, US 2003/0144252, WO 01/87336, US 2002/0031515 A1, WO 01/87334, WO 02/05791, WO 02/09754, US 2003/0157097, US 2002/0076408, WO 02/055106, WO 02/070008, WO 02/089842 and WO 03/86467.
Patients treated with the HER2 antibody trastuzumab may be selected for therapy based on HER2 overexpression/amplification. See, for example, WO99/31140 (Paton et al.), US2003/0170234A1 (Hellmann, S.), and US2003/0147884 (Paton et al.); as well as WO01/89566, US2002/0064785, and US2003/0134344 (Mass et al.). See, also, US2003/0152987, Cohen et al., concerning immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) for detecting HER2 overexpression and amplification.
WO2004/053497 and US2004/024815A1 (Bacus et al.), as well as US 2003/0190689 (Crosby and Smith), refer to determining or predicting response to trastuzumab therapy. US2004/013297A1 (Bacus et al.) concerns determining or predicting response to ABX0303 EGFR antibody therapy. WO2004/000094 (Bacus et al.) is directed to determining response to GW572016, a small molecule, EGFR-HER2 tyrosine kinase inhibitor. WO2004/063709, Amler et al., refers to biomarkers and methods for determining sensitivity to EGFR inhibitor, erlotinib HCl. US2004/0209290, Cobleigh et al., concerns gene expression markers for breast cancer prognosis.
Patients treated with pertuzumab can be selected for therapy based on HER activation or dimerization. Patent publications concerning pertuzumab and selection of patients for therapy therewith include: WO01/00245 (Adams et al.); US2003/0086924 (Sliwkowski, M.); US2004/0013667A1 (Sliwkowski, M.); as well as WO2004/008099A2, and US2004/0106161 (Bossenmaier et al.).
Cronin et al., Am. J. Path., 164(1):35-42 (2004) describes measurement of gene expression in archival paraffin-embedded tissues. Ma et al., Cancer Cell, 5:607-616 (2004) describes gene profiling by gene oliogonucleotide microarray using isolated RNA from tumor-tissue sections taken from archived primary biopsies.
Adjuvant Therapy
Adjuvant therapy, in the broadest sense, is treatment given in addition to the primary therapy to kill any cancer cells that may have spread, even if the spread cannot be detected by radiologic or laboratory tests. Contemporary clinical trials have evaluated the efficacy of chemotherapeutic agents for breast cancer adjuvant therapy, namely BCIRG 001 (comparing paclitaxel, doxorubicin, and cyclophosphomide (TAC) to fluorouracil, doxorubicin, and cyclophosphomide FAC); CALGB 9741 (dose dense tiral); and CALGC 9344 (anthracycline+cyclosphosphomide (AC) compared to AC+paclitaxel (AC/T)).
In the BCRIG 001 trial, the disease free survival (DFS) hazard ratio was 0.72 (p=0.0010), 5 year DFS for TAC was 75%, and for FAC was 68%. Overal survival (OS) hazard ratio was 0.70 (p=0.0080), 5 year OS for TAC was 87%, and for FAC was 81%. For HER2 positive (HER2+) subjects (n=328) in this trial, DFS hazard ratio was 0.60 (p=0.0088).
CALGB 9741 was a dose dense trial comparing AC×4 to T×4; sequential A×4 to T×4 to C×4; dose dense sequential A×4 to T×4 to C×4; and dose dense AC×4 to T×4 (A=anthracycline; C=cyclophosphomide; T=paclitaxel). DFS hazard ratio (dose dense versus standard) was 0.74 (p=0.010); 4 year DFS was 82% versus 75%. OS hazard ratio (dose dense versus standard) was 0.69 (p=0.013).
CALGB 9344 compared the efficacy of AC to AC/T. DFS hazard ratio was 0.83 (p=0.002), with 5 year DFS of 65% for AC and 70% for AC/T. OS hazard ratio was 0.82 (p=0.0064), with 5 year OS for AC of 77% and for AC/T of 80%.
According to the American Cancer Society, an estimated 211,000 women will be diagnosed with breast cancer and approximately 40,000 women will die of the disease in the United States in 2005. Breast cancer is the most common cause of cancer among women in the United States and a woman is diagnosed with breast cancer in the United States every three minutes. About 30% of women diagnosed with breast cancer will have lymph node-positive breast cancer.
Publications or seminars related to adjuvant therapy include: Paik et al., J. Natl. Cancer Inst., 92(24):1991-1998 (2000); Paik et al., J. Natl. Cancer Inst., 94:852-854 (2002); Paik et al. Successful quality assurance program for HER2 testing in the NSABP Trial for Herceptin. San Antonio Breast Cancer Symposium, 2002; Roche P C et al., J. Natl. Cancer Inst., 94(11):855-7 (2002); Albain et al., Proceedings of the American Society of Clinical Oncology Thirty-Eighth Annual Meeting, May 18-21 2002, Orlando, Fla., Abstract 143; The ATAC (Arimidex, Tamoxifen Alone or in Combination) Trialists' Group, Lancet, 359:2131-39 (2002); Geyer et al., 26th Annual San Antonio Breast Cancer Symposium (SABCS), December 2003, Abstract 12; Perez et al., Proc. ASCO, 2005, Abstract 556.
U.S. Patent Publication No. 2004/0014694 (published Jan. 22, 2004) describes a method of adjuvant therapy for the treatment of early breast cancer, comprising administration of docetaxel, doxorubicin and cyclophosphamide.